Fan



Nov. 30,1937. w H; Howfi mq 2,100,481

7 FAN Original Filed. Jan. 26 1933 3 Sheets-Sheet 1 Nov. 30,1937. w, H, HowDEN FAN Original Filed Jan. 26, 1953 3 Sheets-Sheet 2 I Nov. 30, 1937' w. H.- HOWDEN H 2,100,431

FAN

Original File d Jan. 26,1953 3 Sheets-Sheet 5 Patented Nov. 30, 1937 i v Application January 26,

I Renewed September 17,1935 I 1' Claim. (erase-114) The present invention relates to "centrifugal fans and more particularly; to fans provided with inlet vanes adapted to be adjusted to control the output o'f 'the'fan."

'ber'31, 1929, is shown a forced draft fan provided with such adjustable "spin controlling vanes. While both designs offan operate in an entirely satisfactory; manner, so far as controllingthe output or the fan by varying the spin of the entering air is concerned," the speci flc designs of vane mechanism are obj ectionable in that they and repair when necessary.

are diiferent for the two types of fan, and expensive to construct, must be built intothe fan casing while the latter is being assembled, and are difficult to inspect'and lubricate and toadJust The primary object of the present invention is 'to provide a single design suitable for-both forced and induced draft fans'whlch shall be ofunitary construction andpractically independent and separate from the fan casing, and which, as to the.

- fan supporting and actuating mechanism, may be largely assembled apart from the fan casing and with the vanes maybe subsequentlyapplied to or removed from the Ian casing without: disturbing {the latter or the rotor and its supports.

A further object isjto provide-a fan supporting j and assemblingmechanism which shall be easily accessible at all'times for-the purpose of inspection, lubrication, and repair.

' Another object is to provide a mechanism which shall operate positively to position all of the vanes with exactness'and with a of wear and lost motion even after long periods of use.

Another object/is to simplify the -va.ne supporting and assembling mechanism with a view to re- 'ducing the cost of manufacture, and minimizing the frictional resistance tofacilitate the operation of thevanes'.

With these and other objects in view as will herein appear, the present invention comprises the fan and fan supporting and assembling mechanlsm'hereina'fterdescribed and more particularly defined in the claim. 7

In the accompanying" drawings illustrating what is now considered the preferred form of the invention, Fig. 1 is a sectional view of an induced draftfan taken on line ll of Fig. 2;

Fig. 2 is a section on line 2-4 of Fig. 1; Fig. 3

- "2,100,481 1 z William Hay Howden, Glasgow, Scotland, "as- .7 signor to B. F. Sturtevant Company, Hyde Park,

, Mass, a corporation of- Massachusetts I is a similar sectionaljview of aforced fanz' Fig. 4 is an end view; of the unitconstructionpf I actuating niechanisingFi g: 5is'*"-a' plan "view," and Fig. 6' ayertical section on line 6-3-6 offFigfl' i, all on an enlarged scale; Fig.7 is a, detail end" elevation of", the conical hub looking {to the "left of Fig. 6, Fig. 8 is an end elevation andfFig. 9a

side elevation of the adjusting ring, Fig. 10- a detail elevation of the face plate, and Fig. 11 is a detail elevation 'of the rear guard ring, all on substantially'half scale of Figs. 4, 5, and 6; t

The present invention is illustrated in connection with a centrifugal fan of the commonand well known type provided withthe customary involute casing with axial intake opening and tangential discharge. These: parts are all of old andwell known construction and are illustratedin Figs. 1,. 2 and '3 of the drawings'and comprise "the rotor 12 mounted on a shaft H which is journaled in suitable bearings IS. The casing lli is formed with a conical eye l1 and communicating and: merging with the eye is the conical inlet I8. For .an induced draft fan, as shown in Figs. 1 and 2, an inlet box- 20, which connects with a suitable duct, is mounted at the inletof the fan'and is provided with the axial, frusto-co'nical wall or partition H to iorm'a chamber or r'ecessin the outerend of the box, which i freiand easy v access to the vane supporting and controlling I v r 30" I such mechanism are positioned. For aforc'ed; r

mechanism and within which certain"parts*ofi draft fanof the type shown inrig's, 'theinletfl box is :oi'nitted' and the air"passes-directly from theatmos'phere through the inlet conedt q The vanes and their mountings are,in'a general way," similar to that, shown -in"the1H agen a p ication Serial No. 403,753,. wherein: afcircular adjusted by a single actuating meanstdvary' the the tan, and .thus 'to yary the output-oi thelatter.

These vanes are shown at 22 andfeaich is pro-I f videdat its outer endjwith a pivot pin .2l which is journaled in the cone inlet l8 and at its inner 1 end is attached to the pivot 26' which is jourhaled in a'conical hub '28 presently to be described in.

detail. As shown'in Figs. 2 and 3,the axis of each vane. is perpendicular to the'conicalinlet l wall and istherefore at an angle with respect to.

the axis'of the'shaft. The arrangementis such that the vanes, when closed, lie on-an approxi mately conical surface.

The conical hub 28, as shown separately in.

detailin Fig. 7, comprises a casting having a series of regularly spaced openings 88 to receive the inner pivot pins 28 of the vanes. On each pin is integrally formed a clip or bracket 32 to which the vane is attached. A ball race 84 is received in a counter-sunk recess adjacent to each opening 88 and is heldin place by a guard:- plate 88. Attached to the inner end ofeach pivot pin 28 last crank'88 having at its end a freely rotatable roller 48 with spherical surface to be engaged by the actuating mechanism.

In order to facilitate the assembly-around the fan shaft of the vane supporting and actuating mechanism, the conical hub28, likeother parts of the apparatus, is split diametrically. The split portions are provided with opposed lugs 42 which are secured together by bolts 44. The hub is- 1 supported by standards or curved arms 48 secured to the outer end of the inlet. cone l8.

The mechanismfor actuating the crank arms 88 to turn the vanes upon their, pivots comprises an actuating ring mounted" within the conical hub 28 to have slight rotational movement therein, and is provided with a series of projections or shoulders on one face to. engage the crank arm.

This actuating ring 48 is shown in axial section in Fig. 6, and in front and side elevation, on a .88, the two parts being positioned by a dowel pin 82 to assure preservation of alignment. The two parts of the actuating ring are reinforced by bolted web plates 84.

The rear face of the 'plate 50 is provided with a series of projections or shoulders 88 defining spaces 88 which receive the rollers 48 of the vane operating cranks 38. As shown in Figs. 8 and 9,

. these projections 88 are pyramidal'in shape to -conform to the general conical structure of the hub. .Since the rollers 40 are closely engaged between adjacent projections 88, any rotation movement of the vanes. As shown in Figs..2 and of the actuatingring causes simultaneousmniform. adjustment of all of the vanes.

[The actuating ring is given rotational movement by means of acontrol shaft, the outer end of which extends to some convenient point for manual or automatic actuation, while the inner end is connected by suitable linkage with the actuating ring 48 so that rotation of the control shaft rotates the ringand causes the adjusting 6. of the drawings, the control shaft Ill, mounted intermediate its lengthvuponthe bearing H, is journa ed at its inner end in, the ball bearings I2 received in a recess I4 in an inwardly projecting portion 18 of the conical hub. As shown in Fig.

8', theactuating ring 48 is provided with a re- 0638 18 to embrace the projection 18. Attached to the control shaft 10 is a double crank arm 88, a the ends of which are pivoted links 82 connected to pins 84 projecting; from the actuating ring 48, the double crank and link arrangement facilitating the'movement of the actuating ring by eliminating the tendency, as where force is applied at a single-point, to cause the link to twist or bind. It will be seen' that rotation of the shaft In in either direction produces a corresponding rotation of' the actuating ring and V consequent adjustment'jofi the inlet, vanes.

In orderto'prevent passage of airto the rotor except through the vanes 22, the inner face of the conical hub 28 is provided with a split guard ring 88, as shown in Fig. "11, the inner diameter of which is only slightly larger than the diameter of the shaft.

In theoperation of my improved construction the rotation of the control shaftimparts through .the connecting cranks and link a rotational movement' to the actuating ring, which in turn through shoulders or projections actuate the crank arms and turn the vanes upon their pivots.

,When the shaft is rotated inone direction the vanes will be .turned'jin 1 the direction toward parallelism. withthe fan shaft to reducethe amount of spin and increase theoutput of the fan. When the control shaft is turned in the opposite direction the vanes will be turned toward closed position to increase. the amount of spin applied to the air and therebyreducefthe fan output.

By the use of the split or divided conical hub,

actuating ring and plates, the supporting and actuating devices may be assembled in halves and then mounted in position surrounding the fan shaft without'disturbing, theirotor. or its supports. When assembled in the fanv the parts are easily accessible for inspection and lubrication since the actuating and control mechanisms are all located at the inner endsfof the vanesand free access is provided even in theinduced draft type through the conical chamber or recess in the side of the inlet box. The annular-space between the inner edge of the plate "of the,

actuating ring and. the fan shaft is suflicient to permit inspection and lubricationof the operating parts within thei'conical hub.

While c the method: or supporting and actuating the inlet vanes has been shown and described inconnection with a fan construction wherein the vanes operate 'tovary the spin imparted to the air entering the fan and thusv control; thel output of the latter, the present invention isnot necessarily limited thereto but may be embodied in other constructions and arrangements wherein the vanes operate to control the output of the fan more or less by throttling the incoming air instead of varying its spin velocity. Havingthus described the invention, what is claimed is:

A fan comprising a rotor,.a casin'gja conical inlet, a .hollow conicalhub' within the inlet, a series of vanes having at their innerends pivots.

journaled in the hub, the of each vane being perpendicular to the'conical wall of the hub, a crank on each pivot extending perpendicularly therefrom, a rotatable ring within and peripherally supported by the. hub and having a series of inwardly extending projections forming slots to receive the ends of the cranks, and control means to rotate the ring to. adjustthe vanes uniformly.

1m nowDEN. 1o 

